A collection of datasets representing a portion of Washington's State Routes created from a combination of Global Positioning System (GPS) data and inertial data are depicted as polylines with measures and State Route identifiers. The location of the lines corresponds to the leftmost general-use lane.
This dataset is unfinished in that it comprises only mainline routes and includes approximately 90% of the ramps.

Purpose: This data set is used for general-purpose mapping and for use as a Linear Referencing System.Supplemental Information:

The data used to create this graphic layer was collected and edited for use in creating a new high accuracy Locational Referencing System for Washington State highways. The current 500k LRS depicts State Routes with one line representing the highways geographic location and the 24k LRS depicts undivided State Routes with one line and divided routes with two lines. This data set contains lines depicting the centerline of one lane (the leftmost general-use lane) in both directions of travel on divided and undivided State Routes.

Attribute Accuracy Report: State Route identifiers are consistent with the Transportation Information and Planning System (TRIPS) database.

Completeness Report: This data set contains 100% of the mainline state routes in the state of Washington and approximately 90% of the ramps.Positional Accuracy:

Horizontal Positional Accuracy:

Horizontal Positional Accuracy Report:

The horizontal accuracy of the GPS and inertial data used to create the State Route lines was tested against photogrammetric quality data (+/- 1 foot) on eight segments of the existing data and survey quality data (+/- 2-5 cm) on eighteen segments of the existing data. For more information about the testing contact Thomas A. Blake (see process step contacts).

Quantitative Horizontal Positional Accuracy Assessment:

Horizontal Positional Accuracy Explanation:

Eight different segments of at least 20 points each were tested against photogrammetric data. The accuracy for all the test points combined (164 points) was 3.297 feet. Of the eight segments, one had a tested accuracy of 5.366 feet.
Eighteen different segments of at least 20 points each were tested against survey data. The accuracy for all the test points combined (380 points) was 1.549 feet. Of the eighteen segments, one had a tested accuracy of 4.082 feet.

Quantitative Horizontal Positional Accuracy Assessment:

Horizontal Positional Accuracy Explanation:

The GPSLRS500kSPS was created by simplifying the GPSLRSIncSPS data layer. Test points were placed using both layers and compared. The max. difference was 5.613 feet. The max. measure (ARM) difference was 0.001 miles with a horizontal offset of 3 feet.

Vertical Positional Accuracy:

Vertical Positional Accuracy Report: Vertical accuracy of this data set has not been determined.

Lineage:

Process Step:

Process Description:

GPS and inertial data were collected, processed, and edited using hardware and software from Trimble and Navstar Mapping Corporation. Additional editing was done with ESRI's ArcView software. Data was also collected with more traditional survey methods using the Trimble 5600 Total Station and incorporated using a program written by the Navstar Mapping Corporation. The final data set is used to generate polylines with measures.

Process Description: The base shapefile was created in ArcCatalog. Polylines with measures were constructed from the GPS point files and inserted into the shapefile using a custom ArcObjects script executed in ArcMap.Process Date: 08/2008Process Contact:

Attributes were then added and the dataset was projected to state plane coordinates. Additional datasets were extracted for the increasing (GPSLRSIncSPS) and decreasing (GPSLRSDecSPS) directions of travel and ramps (GPSLRSRampsSPS). The GPSLRSIncSPS dataset was then simplified with a three foot tolerance to produce the GPSLRS500kSPS dataset. Using the GPSLRSIncSPS dataset and tabular data from TRIPS, DOT regional polygons were constructed and then used to clip out regional GPSLRS datasets from the GPSLRSIncDecRampsSPS dataset.

Attribute Label: LRS_DATEAttribute Definition: The version date of the dataset.

Attribute:

Attribute Label: LRS_SRIDAttribute Definition:

A unique State Route identifier: *For mainline State Routes, the unique identifier is comprised of the State Route number and "i" or "d" to indicate the direction of travel. "i" refers to travel from south to north or west to east. "d" refers to travel from north to south or east to west. *For State Routes possessing a Related Roadway Type, the unique identifier is comprised of the State Route number, Direction of Travel, Related Roadway Type and Related Roadway Qualifier, as defined by the Transportation Data Office.

A State Route identifier assigned by WSDOT's Transportation Data Office associated with the TRansportation Information and Planning Support system (TRIPS). Every WSDOT highway in Washington state is assigned a State Route number, including interstates and U.S. Routes.

Entity and Attribute Overview: Polylines represent the leftmost general use lane of travel along Washington State Routes. The data set contains State Route numbers, State Route IDs, and direction of travel for state routes.

The Washington State Department of Transportation shall not be liable for any activity involving this data with regard to lost profits or savings or any other consequential damages; or the fitness for use of the data for a particular purpose; or the installation of the data, its use, or the results obtained.

Standard Order Process:

Digital Form:

Digital Transfer Information:

Format Specification: Various formats are used: ESRI coverages and shapefiles, and data tables for placement as ArcView "events."Format Information Content:

The standard distribution compact disc contains all geospatial data sets created by the Washington State Dept. of Transportation. Refer to the included Geodata.txt text file for a brief description of the directory structure.
Data formats vary--most data are stored as ESRI shape files, but some data models require coverages. There are also dbf-format tables of data located by geographic coordinates or State Route Accumulated Route Mileage.

Digital Transfer Option:

Offline Option:

Offline Media: CD-ROM

Fees: noneOrdering Instructions: Call, email or write the Distributor with requests for geo-spatial data sets.Turnaround: Generally, the standard compact disc containing all distributed data can be sent within one week of receiving a data request.

Depends on the data set. Arc/Info coverage or shape file; metadata report in html and text files; and, in some cases, a data dictionary text file. Some data sets in the standard distribution are tabular data for placement as ArcView "events."

Non-digital Form: The Cartography/GIS Section can plot maps of most geospatial data sets.Fees: depend on plotting costs.Ordering Instructions: Contact the Point of Contact listed under the Identification Section to determine the availability of this data set in a non-digital representation.